The aim of this study was to evaluate the changes in the temporomandibular area of the jaw in patients with TMD and the relationship between age, sex, and type of change using CBCT.

TMD is a major public health problem that can disturb the health of affected individuals. It has a multifactorial etiology associated with several risk elements that play a major role in the initiation, spread, and exacerbation of TMD symptoms [20]. Identifying these factors is crucial in determining the appropriate treatment [21]. Understanding TMD prevalence, incidence, and other characteristics in populations around the world can help improve diagnostic methods and prevent the development of TMD. The dental practitioners frequently encounter patients with TMDs, and addressing this condition is important for maintaining the overall health and well-being of affected individuals.

CBCT has been recognized as a reliable method for the examination of the osseous components of the TMJ. This technique is easy to perform, is reproducible and delivers a relatively low dose to the patient. Its usefulness has been previously described in the literature [22].

In the present study, various forms of bony changes including osteophyte, erosion, sclerosis, flattening, ankylosis, Ely cyst, hyperplasia and hypoplasia in the condyle were observed. In addition, influence of bony changes on each other was assessed considering P value = 0.05. Results showed that presence or absence of radiologic lesion in one side of condyle does not affect the presence or absence of lesion in other side.

In our study, 62% of patients were female and 38% were male. Similarly, many studies have concluded that TMD is more frequent in women than men [18, 22,23,24]. The greater occurrence in women may be explained by the hormonal influences of estrogen and prolactin, which may exacerbate degradation of cartilage and articular bone in addition to stimulating a series of immunological responses in the TMJ [25, 26]. As a result, Sex is a significant risk factor for TMJ disorders apart from parafunctional habits.

Based on the findings of the findings of the current study, the prevalence of bony changes in the TMJ are as follows:

1-Osteophyte (63.5%) 2-Flattening (42%) 3-Erosion (40%) 4-Ankylosis (12.5%) 5-Sclerosis (10%) 6-condylar Hyperplasia (7.5%) 7-condylar Hypoplasia (2%) and 8-Ely cyst (1%).

This result was in accordance with that of dos Anjos Pontual [18] and contrary to the study of Zhao et al., Bae et al. [14, 19]. With regard to combinations of bone changes, osteophytes accompanied by flattening was more prevalent in our study, differing from the findings by K. S. Nah [9] that found sclerosis as the most prevalent bony change.

According to the present study, the mean age of patients with ankylosis in the condylar head was 28 years old (P value = 0.032) which was statistically significantly compared to patients without ankylosis (34 years old). These results are in agreement with the findings of L. B. Kaban et al. [27] and Dongmei He et al. [28]. It suggests that ankylosis of the condylar head is more likely to occur at a younger age, and highlights the importance of early detection and intervention for this condition to prevent further complications and improve outcomes.

The present results showed a significant relationship between age and Ely Cyst. These finding are consistent with previous studies conducted by Sun mee bae et al. studies [19].

Emshof et al. [24] found that 60% of patients with mean age of 37 had erosion. In this study 39% of patients with mean age of 34 had erosion.

Similar to findings of Cömert Kiliç S et al. [29], our study showed no significant relationship between aging and prevalence of degenerative bony changes of TMJ.

In our study, we found that bilaterally occurring osteophyte were significantly more common than unilateral osteophytes in both male and female subjects. However, we did not observe a significant association between bilateral and unilateral occurrence of other studied bony changes. These results are consistent with those reported by A. M. Ferraz et al. [30].

The present results found no significant relationship between age and condylar erosion. This result contrasts with the findings of studies of M. Imanimoghaddam [12], who reported a positive correlation between age and the prevalence of condylar erosion. This disagreement could be attributed to the differences in the age distribution of the study populations, as well as variations in the diagnostic criteria used to assess condylar erosion.

Our study found no statistically significant association between age and osteophyte which is opposite to K. Alexiou et al. [22] and Paknahad et al. [31] findings that concluded the prevalence of osteophyte increases with age. The discrepancy in results may be due to differences in study population. Additionally, genetic and environmental factors may contribute to the development and progression of osteophytes, which could var across different populations and geographic regions.

Our study found a significant negative correlation between age and sclerosis, as evidenced by the statistically significant difference in mean age between patients with and without sclerosis. Specifically, we observed a decrease in the prevalence of sclerosis with increasing age. This result contradicts the findings of K. Alexiou et al. [22] who reported a positive correlation between age and sclerosis. This disagreement could be attributed to the different methodologies, patient population or random variations in the data.

Indeed, further investigations with larger sample sizes are needed to confirm or refute the results of the present investigation. This study has some design and technical limitations. First, since it was a retrospective study, it was difficult to clearly classify complex clinical symptoms. Second, the fluctuating nature of TMD symptoms and signs was not contemplated in the cross-sectional design [32].

It would be beneficial to conduct longitudinal studies to better understand the progression and natural history of TMD signs and symptoms. This would provide valuable insights into the underlying mechanisms and potential treatment options for TMD. Moreover, utilizing magnetic resonance imaging (MRI) would provide detailed information on soft tissue changes in TMD. This could help identify specific structural abnormalities or abnormalities in the TMJ that may be associated with TMD symptoms. Lastly, studying TMD in children would be important as it could provide insights into the early development and progression of TMD. Understanding the factors that contribute to TMD in children could potentially lead to early interventions and prevention strategies.